Canada Geese Research Articles

Behavioral in-air audiogram of two Arctic fox (Alopex lagopus) at the Columbus Zoo and Aquarium

The aerial audiograms of two captive adult, male Arctic fox (Alopex lagopus) were measured using a two-alternative, forced-choice paradigm and descending staircase method of signal presentation at the Columbus Zoo and Aquarium. Both fox displayed a typical mammalian U-shaped audiometric curve, with a functional hearing range of 125 Hz to 16 kHz (sensitivity < 60 dB re: 20 μPa) and average peak sensitivity of 22 dB re: 20 μPa at 4 kHz. This range is similar to airborne hearing thresholds previously measured for two closely related species, the kit fox (Vulpes marotis) and the domestic dog (Canis familiaris). There was little variability around threshold and no significant difference between the hearing curves of the two fox. The peak sensitivities of the Arctic fox overlaps their vocal range, the vocal range of their prey; field voles (Microtus agrestis), collared lemmings (Dicrostonyx groenlandicus), Canada geese (Branta canadensis), and the hearing range of a predator; the polar bear (Ursus maritimus). Ambient noise levels were monitored and test frequencies below 5 kHz were possibly masked. Potential response bias was examined using Receiver Operator Characteristic analysis and had a conservative bias. Masking effects and conservative response bias may have resulted in slightly underestimated hearing curves.

Beavers (Castor canadensis) facilitate early access by Canada geese (Branta canadensis) to nesting habitat and areas of open water in Canada's boreal wetlands

Several studies demonstrate how beavers influence waterfowl habitat availability, ultimately improving waterfowl breeding success; however, no current research links beavers to early season nesting activities of Canada geese (Branta canadensis) in northern climates. We examined how beavers facilitate early access to open water for geese at Miquelon Lake Provincial Park (MLPP), Canada. We surveyed 32 active and 39 inactive beaver ponds to examine whether beavers facilitate early access to open water. Open water occurred 10.7 days earlier at active beaver ponds (mean ice-off day=87.54, s=13.88) than inactive ponds (mean ice-off day=98.19, s=9.07), especially adjacent to main lodge entrances and winter food caches. Snowpack was on average 5.9cm shallower at active ponds. Prior to availability of open water, Canada geese exhibited intraspecific territoriality over beaver lodges as nest sites and once water was present, preferred island lodges over bank lodges. These findings support other studies that examined island nesting as protection from terrestrial predators and highlight the importance of beavers in creating open water areas earlier in the season.

Evaluation of an off-the-shelf Unmanned Aircraft System for Surveying Flocks of Geese

Abstract. Small off-the-shelf unmanned aircraft systems (UAS) could prove useful for surveying waterbirds. A low-end model was evaluated for surveying flocks of Canada Geese (Branta canadensis) and Snow Geese (Chen caerulescens) by comparing photographic counts from repeated flybys to repeated visual ground counts. Due to low contrast of Canada Geese with the ground, UAS counts based on confident detections only had a lower mean than ground counts for five out of six flocks (>30% lower for three flocks) and coefficients of variation (CV) ranging from 11–106%, compared to 1–6% for ground counts. Conversely, UAS counts of high-contrast Snow Geese were 60% higher on average and less variable (CV = 1–6%) than ground counts (CV = 11%). In some cases the aircraft likely detected birds that were not seen from the ground due to an obstructed view. Shortcomings of the UAS were mainly related to its unsophisticated imaging system compared to more expensive models. Otherwise, the UAS proved capable of being convenie...

The effects of anthropogenic alteration of nesting habitat on rates of extra‐pair fertilization and intraspecific brood parasitism in Canada Geese Branta canadensis

Parentage studies have shown that alternative reproductive strategies are widespread in many avian taxa that were once thought to be monogamous. Recent anthropogenically mediated habitat change may have disrupted ecological factors, such as breeding density, which have given rise to inter‐ and intraspecific variation in the frequency of extra‐pair fertilization (EPF) and intraspecific brood parasitism (IBP). We used genetic analyses to quantify the incidence of alternative reproductive strategies exhibited within clutches of Canada Geese Branta canadensis maxima nesting in high‐ and low‐density situations in and around urban areas in southern Michigan, USA. We tested the hypothesis that high nesting density would increase the frequency of EPF and IBP. There were no significant differences in rates of EPF and IBP clutches (14 and 26% of clutches, respectively) from nests in high‐density (21.7% EPF, 21.7% IBP) vs. low‐density (5.3% EPF, 31.6% IBP) areas, although high‐density sites had a fourfold higher rate of EPF. Rates of EPF and IBP in high‐density urban areas in Michigan were comparable to rates observed in other species nesting under different ecological conditions. Levels of relatedness between host and parasitic females were higher than expected by chance, suggesting that related females are more tolerant of one another and that host females could gain inclusive fitness benefits from rearing parasitic offspring. Our study highlights the importance of understanding the different costs and benefits associated with alternative behavioural repertoires that may vary as habitats and associated selection pressures are increasingly modified by human activities.

Delayed nesting by female Canada Geese (Branta canadensis): Benefits and costs

ABSTRACT. In many avian species, females do not nest the first year they attain sexual maturity. I examined the benefits and costs of delayed nesting in a nonmigratory population of Canada Geese (Branta canadensis) in New Haven County, Connecticut, from 1984 through 2008. I individually marked 381 female goslings and monitored them throughout their lives. Eighty-seven females were recruited into the local breeding population; 16 of these started nesting when 1 or 2 years old (young nesters), and 71 started nesting when 3 to 9 years old (delayed nesters). During their first reproductive effort, young nesters and delayed nesters produced similar-sized clutches but young nesters produced fewer hatchlings or fledglings. Young nesters died sooner than delayed nesters, but the two groups were similar in number of years of life following first nesting effort, number of nesting years during life span, and total lifetime production of eggs, hatchlings, and fledglings. Both young nesters and delayed nesters had sim...

Assessment of bias in US waterfowl harvest estimates

Context North American waterfowl managers have long suspected that waterfowl harvest estimates derived from national harvest surveys in the USA are biased high. Survey bias can be evaluated by comparing survey results with like estimates from independent sources. Aims We used band-recovery data to assess the magnitude of apparent bias in duck and goose harvest estimates, using mallards (Anas platyrhynchos) and Canada geese (Branta canadensis) as representatives of ducks and geese, respectively. Methods We compared the number of reported mallard and Canada goose band recoveries, adjusted for band reporting rates, with the estimated harvests of banded mallards and Canada geese from the national harvest surveys. We used the results of those comparisons to develop correction factors that can be applied to annual duck and goose harvest estimates of the national harvest survey. Key results National harvest survey estimates of banded mallards harvested annually averaged 1.37 times greater than those calculated from band-recovery data, whereas Canada goose harvest estimates averaged 1.50 or 1.63 times greater than comparable band-recovery estimates, depending on the harvest survey methodology used. Conclusions Duck harvest estimates produced by the national harvest survey from 1971 to 2010 should be reduced by a factor of 0.73 (95% CI = 0.71–0.75) to correct for apparent bias. Survey-specific correction factors of 0.67 (95% CI = 0.65–0.69) and 0.61 (95% CI = 0.59–0.64) should be applied to the goose harvest estimates for 1971–2001 (duck stamp-based survey) and 1999–2010 (HIP-based survey), respectively. Implications Although this apparent bias likely has not influenced waterfowl harvest management policy in the USA, it does have negative impacts on some applications of harvest estimates, such as indirect estimation of population size. For those types of analyses, we recommend applying the appropriate correction factor to harvest estimates.

Species Associations and Habitat Influence the Range-Wide Distribution of Breeding Canada Geese (Branta canadensis interior) on Western Hudson Bay

Abstract. Inter- and intra-specific interactions are potentially important factors influencing the distribution of populations. Aerial survey data, collected during range-wide breeding population surveys for Eastern Prairie Population (EPP) Canada Geese (Branta canadensis interior), 1987–2008, were evaluated to assess factors influencing their nesting distribution. Specifically, associations between nesting Lesser Snow Geese (Chen caerulescens caerulescens) and EPP Canada Geese were quantified; and changes in the spatial distribution of EPP Canada Geese were identified. Mixed-effects Poisson regression models of EPP Canada Goose nest counts were evaluated within a cross-validation framework. The total count of EPP Canada Goose nests varied moderately among years between 1987 and 2008 with no long-term trend; however, the total count of nesting Lesser Snow Geese generally increased. Three models containing factors related to previous EPP Canada Goose nest density (representing recruitment), distance to Hud...

Molecular detection of novel picornaviruses in chickens and turkeys

Fecal specimens, including swabs and litter extracts, collected from chickens, domestic ducks, turkeys, and Canadian geese were tested using degenerate primers targeting regions encoding for conserved amino acid motifs (YGDD and DY(T/S)(R/K/G)WDST) in calicivirus RNA-dependent RNA polymerases. Similar motifs are also present in other RNA viruses. Two fecal specimens and 18 litter extracts collected from chickens and turkeys yielded RT-PCR products. BLAST search and phylogenetic analysis revealed that all amplicons represented picornaviruses that clustered into two major groups. Four chicken and one turkey samples yielded 250 bp amplicons with 84–91% nucleotide identity to the recently described turkey hepatitis viruses, while 280 and 283 bp amplicons obtained from 11 chicken and 4 turkey samples represented novel picornaviruses with the closest nucleotide identity to kobuviruses (54–61%) and turdiviruses (47–54%). Analysis of 2.2–3.2 kb extended genome sequences including the partial P2 (2C) and complete P3 (3A, 3B (VPg), 3Cpro, and 3Dpol) regions of selected strains indicated that viruses yielding the 280/283 bp amplicons represent a putative new genus of Picornaviridae. The 3′-non-translated region (NTR) of the turkey hepatitis-like viruses described in this study was significantly longer (641–654 nt) than that of any of the other piconaviruses and included a putative short open reading frame (ORF). In summary, we report the molecular detection of novel picornaviruses that appear to be endemic in both chickens and turkeys.

Foraging preferences of Canada geese among turfgrasses: Implications for reducing human–goose conflicts

AbstractCanada geese (Branta canadensis) can cause serious damage to turfgrass areas and create human health and safety concerns (e.g., collisions with aircraft, disease transmission). We conducted a study during 2005–2007 to determine if Canada geese exhibit a feeding preference among various commercially available turfgrasses. Behavioral responses of captive geese to 9 turfgrasses, bare ground, and litter were observed over 6 4‐week trials during July–September following the installation of selected turfgrasses into experimental arenas. Captive geese preferred to forage on Kentucky bluegrass, creeping bentgrass, and fine fescue sods compared to centipedegrass, St. Augustinegrass, and zoysiagrass. Forage qualities and macronutrient levels varied among the turfgrasses and might explain the foraging preferences geese exhibited during this study. Canada goose feeding rate was positively correlated with crude protein, nitrogen content, and calcium, but negatively correlated with acid detergent fiber content, within various turfgrasses. Our findings suggest careful selection of turfgrasses could be an effective method for reducing Canada goose conflicts in urban and suburban areas. © 2011 The Wildlife Society.

Faecal indicators and pathogens in selected New Zealand waterfowl

Freshly excreted droppings from Canada geese (n=80), black swans (n=80), ducks (n=80) and gulls (n=80) were collected from sites around New Zealand. The droppings were enumerated for Escherichia coli, enterococci and Salmonella spp., and for the presence/absence of Cryptosporidium spp. Overall prevalence of E. coli and enterococci in samples was 95% and 94%, respectively. Cryptosporidium spp. was detected in 2% of the samples, whereas no Salmonella spp. were detected in the survey. Preliminary estimates of daily microbial outputs suggest that ducks will produce the highest loadings of E. coli and enterococci per bird, whereas Canada geese will produce the highest loadings of Campylobacter spp. per bird. This study provides the first set of indicator and pathogen counts for one of the largest sources of diffuse faecal contamination of natural waters in New Zealand.

Population Growth and Movements of Canada Geese in New Haven County, Connecticut, during a 25-Year Period

In the last few decades, Canada Geese (Branta canadensis) have become established in metropolitan areas throughout North America. From 1984 through 2009, Canada Geese in New Haven County, Connecticut, were banded as goslings (HY geese) and adults (AHY), and their movements and recruitment into the local breeding population were documented. During this period, the number of Canada Geese increased several fold in Connecticut. Geese were non-migratory; most recoveries (85%) of banded Canada Geese came from Connecticut, and 76% came from New Haven County. Dispersal rates outside of Connecticut peaked during 1990–1994 when 23% of all reported geese were shot outside of the state; more recently (2005–2009) only 3% of reported geese were shot outside 0f Connecticut. The proportion of dispersing geese that moved northward in the Atlantic Flyway has increased in recent years. Similar proportions 0f AHY females (23%) and AHY males (22%) were recruited into the local breeding population. Among HY geese, more females (22%) than males (5%) were recruited because HY males were more likely to disperse out of the county than HY females. Non-migratory populations of geese in metropolitan areas are causing nuisance problems; the restricted movements of these geese indicate that efforts to reduce their populations will have to be conducted at the local level.

Genetic Markers for Rapid PCR-Based Identification of Gull, Canada Goose, Duck, and Chicken Fecal Contamination in Water

Avian feces contaminate waterways but contribute fewer human pathogens than human sources. Rapid identification and quantification of avian contamination would therefore be useful to prevent overestimation of human health risk. We used subtractive hybridization of PCR-amplified gull fecal 16S RNA genes to identify avian-specific fecal rRNA gene sequences. The subtracters were rRNA genes amplified from human, dog, cat, cow, and pig feces. Recovered sequences were related to Enterobacteriaceae (47%), Helicobacter (26%), Catellicoccus (11%), Fusobacterium (11%), and Campylobacter (5%). Three PCR assays, designated GFB, GFC, and GFD, were based on recovered sequence fragments. Quantitative PCR assays for GFC and GFD were developed using SYBR green. GFC detected down to 0.1 mg gull feces/100 ml (corresponding to 2 gull enterococci most probable number [MPN]/100 ml). GFD detected down to 0.1 mg chicken feces/100 ml (corresponding to 13 Escherichia coli MPN/100 ml). GFB and GFC were 97% and 94% specific to gulls, respectively. GFC cross-reacted with 35% of sheep samples but occurred at about 100,000 times lower concentrations in sheep. GFD was 100% avian specific and occurred in gulls, geese, chickens, and ducks. In the United States, Canada, and New Zealand, the three markers differed in their geographic distributions but were found across the range tested. These assays detected four important bird groups contributing to fecal contamination of waterways: gulls, geese, ducks, and chickens. Marker distributions across North America and in New Zealand suggest that they will have broad applicability in other parts of the world as well.

Lactobacillus brantae sp. nov., isolated from faeces of Canada geese (Branta canadensis)

Three strains of lactic acid bacteria (LAB) were isolated from the faeces of apparently healthy wild Canada geese (Branta canadensis) in 2010 by cultivating faecal LAB on Rogosa SL agar under aerobic conditions. These three isolates were found to share 99.9 % gene sequence similarity of their 16S rRNA, their 16S-23S intergenic transcribed spacer region (ITS), partial 23S rRNA, rpoB, rpoC, rpoA and pheS gene sequences. However, the three strains exhibited lower levels of sequence similarity of these genetic targets to all known LAB, and the phylogenetically closest species to the geese strains were Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus saniviri. In comparison to L. casei ATCC 393(T), L. paracasei ATCC 25302(T), L. rhamnosus ATCC 7469(T) and L. saniviri DSM 24301(T), the novel isolates reacted uniquely in tests for cellobiose, galactose, mannitol, citric acid, aesculin and dextrin, and gave negative results in tests for l-proline arylamidase and l-pyrrolydonyl-arylamidase, and in the Voges-Proskauer test. Biochemical tests for cellobiose, aesculin, galactose, gentiobiose, mannitol, melezitose, ribose, salicin, sucrose, trehalose, raffinose, turanose, amygdalin and arbutin could be used for differentiation between L. saniviri and the novel strains. On the basis of phenotypic and genotypic characteristics, and phylogenetic data, the three isolates represent a novel species of the genus Lactobacillus, for which the name Lactobacillus brantae sp. nov. is proposed. The type strain is SL1108(T) (= ATCC BAA-2142(T) = LMG 26001(T) = DSM 23927(T)) and two additional strains are SL1170 and SL60106.

The possibility of obtaining intergeneric hybrids via White Kołuda ( Anser anser L.) goose insemination with fresh and frozen-thawed Canada goose ( Branta canadensis L.) gander semen

The objective of the present experiments was to produce the intergeneric hybrids of domesticated and wild goose via artificial insemination with fresh and frozen-thawed semen. The experiments were carried out during two successive goose reproductive seasons, on eight five-year-old Canada Goose ( Branta canadensis L.) males used as semen donors and 16 two-year-old White Kołuda geese designated to fertility tests. Pooled semen was collected twice a week by the dorso-abdominal massage. In freshly collected semen, ejaculate volume, color, consistency, degree of fecal or blood contamination, spermatozoa concentration, motility, and morphology were evaluated. Part of the semen collected in the first year of the experiment (Experiment 1) was used for geese insemination with fresh semen, while the remainder was frozen. In Experiment 2 all samples were subjected exclusively to freezing procedure. Geese were inseminated once a week with fresh semen in a dose of 80 μl or 160 μl, and twice a week with frozen-thawed semen in a dose of 80 μl (160 μl per wk) or 100 μl (200 μl per wk). Eggs were set weekly and incubated up to hatching. The volume of ejaculates varied from 0.100 to 0.470 ml; spermatozoa concentration from 140 to 310 million ml −1; progressive movement was observed in 40 to 60% of spermatozoa; the percentage of total live spermatozoa ranged from 69.3 to 92.0%, the highest percentage (34.0–68.3) was represented by live normal spermatozoa and those with bulb-head (13.3–41.0). Cryopreservation caused a decrease in percentage of motile cells to 30%; total live spermatozoa contribution by 27.2%p, including those live normal by 15.9%p (in relation to the fresh semen), bulb-head spermatozoa by 10.9%p, and increase (by 5.9%p) in number of spermatozoa with other deformations. Goose insemination 1×/week with fresh semen containing about 10.3 million live normal spermatozoa resulted in 66.7% of fertile eggs and with dose higher by 2.8 million spermatozoa (on average) the fertility increased by 20.9%p (up to 87.6% on average). Hatchability from set and fertile eggs was 55.9% and 83.9% vs. 66.3% and 75.6%, respectively. After twice a week insemination with frozen-thawed semen containing about 10.2 million live normal cells 58.2% eggs were fertile; hatchability from set eggs was 42.8% and from fertile eggs 71.7%, while insemination dose increase by 2.7 million spermatozoa per week caused a fertilization increase by 3.8%p (62.0% on average), this increase was not statistically significant, but hatchability from the fertile eggs (95.4%), was significantly (P < 0.05) higher. The use of AI with fresh semen in the creation of intergeneric hybrids of Canada goose males and White Kołuda females allows a high level of egg fertility to be obtained. Furthermore, one limitation which is the short reproductive season of the Canada goose may be overcome by the use of cryopreserved semen.

Anthraquinone repellent to reduce take of non-target birds from zinc phosphide rodenticide applications

We evaluated anthraquinone as an avian repellent to reduce take of non-target birds from zinc phosphide rodenticide applications. We observed zero mortalities and no overt signs of zinc phosphide toxicosis among 20 Canada geese ( Branta canadensis), 24 horned larks ( Eremophila alpestris), and 47 ring-necked pheasants ( Phasianus colchicus) offered baits treated with 1% or 2% anthraquinone and 2% zinc phosphide (target concentrations; wt/wt) during laboratory performance experiments. Thus, anthraquinone successfully prevented consumption of 2% zinc phosphide baits among non-target birds in captivity. We observed 10% mortality among black-tailed prairie dogs (i.e., target rodent; Cynomys ludovicianus) offered oats treated with 1% anthraquinone and 2% zinc phosphide, and 30% mortality among black-tailed prairie dogs offered oats treated with 2% anthraquinone and 2% zinc phosphide. Upon completion of our experiments, chemical analyses indicated that actual concentrations were 1.66% and 1.45% zinc phosphide among oats treated with1% anthraquinone + 2% zinc phosphide, and 2% anthraquinone + 2% zinc phosphide, respectively. We observed 24–37% repellency during a concentration–response test with black-tailed prairie dogs offered corn seeds treated with 0.5–4% anthraquinone (target concentrations; wt/wt). Thus, anthraquinone may affect consumption of repellent-treated rodenticide baits for black-tailed prairie dogs. Supplemental performance testing and field efficacy studies (e.g., 0.25–0.5% anthraquinone and 2% zinc phosphide, actual concentrations; wt/wt) are necessary for further development of an efficacious, bird-repellent rodenticide bait.

Detection and Characterization of a Distinct Bornavirus Lineage from Healthy Canada Geese (Branta canadensis)

Avian bornaviruses (ABV), identified in 2008, infect captive parrots and macaws worldwide. The natural reservoirs of these viruses are unknown. Reverse transcription-PCR (RT-PCR) was used to screen oropharyngeal/cloacal swab and brain samples from wild Canada geese (Branta canadensis) for ABV. Approximately 2.9% of swab samples were positive for bornavirus sequences. Fifty-two percent of brain samples from 2 urban flocks also tested positive, and brain isolates were cultured in duck embryo fibroblasts. Phylogenetic analyses placed goose isolates in an independent cluster, and more notably, important regulatory sequences present in Borna disease virus but lacking in psittacine ABVs were present in goose isolates.

Successful Management of Simple Fractures of the Femoral Neck With Femoral Head and Neck Excision Arthroplasty in Two Free-living Avian Species

A red-tailed hawk (Buteo jamaicensis) and a Canada goose (Branta canadensis) were evaluated for unilateral pelvic limb lameness. Physical examination findings and results of diagnostic imaging revealed femoral neck fractures in both birds. Both birds were treated with a femoral head and neck excision arthroplasty. The affected legs were not immobilized, and the birds were encouraged to use the legs immediately after surgery to encourage formation of a pseudoarthrosis. Within 2 weeks, both birds were using the affected limb well enough to be either successfully released or transferred to a wildlife rehabilitation facility. Femoral head and neck excision arthroplasty without immobilization of the limb is recommended for managing avian femoral neck fractures, especially in free-ranging species in which a rapid and complete or near complete return to function is vital for survival in the wild.

Factors Associated with Dusky Canada Goose (Branta Canadensis Occidentalis) Nesting and Nest Success on Artificial Nest Islands of the Western Copper River Delta

Decline of the Dusky Canada Goose (Branta canadensis occidentalis; hereafter, Dusky Goose) population on the western Copper River Delta (CRD) prompted the establishment of an artificial nest island (island) program in 1983. A retrospective analysis of the program was conducted to examine general trends in island use and nest success from 1984–2005. A series of candidate models was generated to determine how habitat, island and biological variables were associated with island use and nest success from 1996–2005. Use of islands by Dusky Geese increased between 1987 and 2005 from 10% to 44%; apparent nest success averaged 64 ± 4% and showed no trend with year. Island use was consistently and strongly associated with the previous year's island status. The odds of nesting on an island that contained a successful nest the previous year were four times greater than for islands not used the previous year. Likelihood of island use was highest at moderate shrub cover and increased with shrub height. Likelihood of nest success increased on islands further from shore. The influence of year suggests the presence of alternate prey and predator abundance is more important to nest success than island features. The increasing use of islands while the CRD Dusky Goose population has been declining indicates that islands may be increasingly important to population productivity. However, quantifying the contribution of the island program requires a better understanding of other population metrics, such as gosling mortality.

Feather barbs as a good source of mtDNA for bird species identification in forensic wildlife investigations

BackgroundThe ability to accurately identify bird species is crucial for wildlife law enforcement and bird-strike investigations. However, such identifications may be challenging when only partial or damaged feathers are available for analysis.ResultsBy applying vigorous contamination controls and sensitive PCR amplification protocols, we found that it was feasible to obtain accurate mitochondrial (mt)DNA-based species identification with as few as two feather barbs. This minimally destructive DNA approach was successfully used and tested on a variety of bird species, including North American wild turkey (Meleagris gallopavo), Canada goose (Branta canadensis), blue heron (Ardea herodias) and pygmy owl (Glaucidium californicum). The mtDNA was successfully obtained from 'fresh' feathers, historic museum specimens and archaeological samples, demonstrating the sensitivity and versatility of this technique.ConclusionsBy applying appropriate contamination controls, sufficient quantities of mtDNA can be reliably recovered and analyzed from feather barbs. This previously overlooked substrate provides new opportunities for accurate DNA species identification when minimal feather samples are available for forensic analysis.

ADVERSE HEALTH EFFECTS IN CANADA GEESE (BRANTA CANADENSIS) ASSOCIATED WITH WASTE FROM ZINC AND LEAD MINES IN THE TRI-STATE MINING DISTRICT (KANSAS, OKLAHOMA, AND MISSOURI, USA)

Lead and zinc poisoning have been recorded in a variety of bird species, including migrating waterfowl such as Canada Geese (Branta canadensis), at sites contaminated with mine waste from lead and zinc mines in the Tri-State Mining District, Kansas, Oklahoma, and Missouri, USA. The adverse health impacts from mine waste on these birds may, however, be more extensive than is apparent from incidental reports of clinical disease. To characterize health impacts from mine waste on Canada Geese that do not have observable signs of poisoning, four to eight apparently healthy birds per site were collected from four contaminated sites and an uncontaminated reference site, and examined for physical and physiologic evidence of metals poisoning. Tissue concentrations of silver, aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, selenium, thallium, vanadium, and zinc were determined by inductively coupled plasma mass spectroscopy. Adverse health effects due to lead were characterized by assessing blood δ-aminolevulinic acid dehydratase (ALAD) enzyme activity. Adverse effects associated with zinc poisoning were determined from histologic examination of pancreas tissues. Elevated tissue lead concentrations and inhibited blood ALAD enzyme activities were consistently found in birds at all contaminated sites. Histopathologic signs of zinc poisoning, including fibrosis and vacuolization, were associated with elevated pancreatic zinc concentrations at one of the study sites. Adverse health effects associated with other analyzed elements, or tissue concentrations indicating potentially toxic exposure levels to these elements, were not observed.